Valvoline 20w-50

[Grego]

Does anyone run 20w-50 in there new rebuilt motors. What about older 100,000+ motors? My machinist highly recommended the Valvoline 20w-50 for the break in oil and for the life duration of the motor. He wrote and circled it on my receipt. WA state climate never too hot never too cold.

[gregorio87]

Hi! I haven't use this oil, but maybe I can explain this arguments:
The first number means the viscosity at low temperature, the second one means the viscosity at high temperature.
So, the SAE number "20W50" means the viscosity of an oil in function of a temperature.
For example, a 20W50 at cold temperature is more viscous than a 10W50; at the engine startup if flow with a little bit more difficulty through the lubricant circuit, making a little higher oil pressure.
I personally think that 20 is too high start value, the oil seems to be jam at engine startup.

[SilverXJ]

I see no reason to use 20w-50 in a new engine unless he set it up with large clearances. Then there is also the issue of ZDDP in the oil. The only line of Valvoline I would use is the VR-1 and teh racing (black bottle). The black bottle isn't really for daily driven 3000+ mile change intervals.

If your clearances are stock or close to I would use a 10w40. Personally I would go with a 5w-30 if oil pressure stays good with it.

On my 95 ZJ w/212,000 miles I run 10w40 synthetic. Al my high mileage Jeeps have ran 10w40.

[Retlaw01XJ]

Edit.... looks like Silver beat me to the answer!!! At least we share the same opinion...

In general, for normal use in moderate temperatures, a 10w-30 will be fine.
If bearing clearances are on the high side and you are seeing low oil pressure, stepping up to a 40 or 50 weight should help.
Valvoline does have a VR-1 racing oil which has higher levels of zinc and phosphorus..... excellent for extra wear protection for cam and lifters.
I just use a major brand 10w-30 with a bottle of zddplus additive to provide extra protection for cam and lifters.

I don't see the need for a heavy 20w-50 for startup. Ask your machinist why he does recommend it. I'm curious why.

[Grego]

He says they have heated 10w-30 oils on a stove at running temperatures and it pretty much has the consistency of water,not very much protection. Also, that today's government has forced the oil companies to remove oil additive zinc in motor oil. I did check clearances as I was assembling and they were at the upper end of spec, but within. The oil he highly recommend was the Valvoline VV851 racing. This is also the oil he recommended adding on top of my assembly lube as I was installing my bearings. Also wene shutting down a motor hot, these lighter oils run off the bearings and components quickly back down into the pan, while a heavier oil stays on the components for protection on a cold startup.

[jsawduste]

You need a more knowledgeable engine builder. He obviously doesn't keep up with the times.

20-50 is going to be hard on cam/dist gears. Be prone to cold start starvation and send a lot of time running with the oil pump bypass spring open.

The "racing" oils do not contain the detergents, anti foam additives and "general" stability a common engine oil designed for everyday use has.That is not to say that any oil off the shelve is good and proper. There are oils that will work just fine with a flat tappet engine that is has the "additives" and zinc phosphate (ZDDP) to keep the engine happy without short drain intervals.

Rather then take our or his word for it. Google a few search words like racing oils or automotive oil additives and educate yourself.

Brad Penn and Joe Gibbs are two oils you should look at REAL hard. 10w-30 is plenty thick for 99% of typical consumer usage.

[Grego]

Thanks for the replys!
Greg.

[racing89]

Agree. Just fired-up my race truck 2x weeks ago that has been in winter storage @ -5c. Started immediatly, then windmilled to a stop. Broke dist. gear with 20/50 castrol.

You need a more knowledgeable engine builder. He obviously doesn't keep up with the times.

20-50 is going to be hard on cam/dist gears. Be prone to cold start starvation and send a lot of time running with the oil pump bypass spring open.

The "racing" oils do not contain the detergents, anti foam additives and "general" stability a common engine oil designed for everyday use has.That is not to say that any oil off the shelve is good and proper. There are oils that will work just fine with a flat tappet engine that is has the "additives" and zinc phosphate (ZDDP) to keep the engine happy without short drain intervals.

Rather then take our or his word for it. Google a few search words like racing oils or automotive oil additives and educate yourself.

Brad Penn and Joe Gibbs are two oils you should look at REAL hard. 10w-30 is plenty thick for 99% of typical consumer usage.

[TXslayer]

A lot of car guys in my area run rotella brand oil since it has all the additives still that they removed from most oils these days. so from what I hear it still has one of the best lubricating properties of any oil yet. I mean hell,if these guys can run these 4cyl import motors to 8-10k rpm I don't see any reason not to run it. I use castrol GTX non-synthetic 10W30 but it's hotter then hell down here. but I've yet to blow a motor. my poor 240sx has 240k miles on it and still has 60psi oil press. at 2k rpm

[jsawduste]

A lot of car guys in my area run rotella brand oil since it has all the additives still that they removed from most oils these days. so from what I hear it still has one of the best lubricating properties of any oil yet. I mean hell,if these guys can run these 4cyl import motors to 8-10k rpm I don't see any reason not to run it. I use castrol GTX non-synthetic 10W30 but it's hotter then hell down here. but I've yet to blow a motor. my poor 240sx has 240k miles on it and still has 60psi oil press. at 2k rpm

Yes Rotella has more additives then conventional but now with the new "clean air" formulations it is`nt the same good stuff as the old formulation. Comparing additive packages for diesel engines and gasoline engines is not the smartest line of logic. The demands are different and so is the oil.

My newer truck gets the newer oils. The 4.x engines were designed around a totally different oil formulation. So I stick to the old stuff.

Brad Penn
Joe Gibbs

And none of this 20w-50 crap. 10w-30 all day long all year long

[Muad'Dib]

FWIW, starting with Comp Cams break in oil with ZDDP Plus 5w30. Now im running Valvoline VR1 5w30 with ZDDP Plus. Just finished the last bottle of ZDDP Plus i have on my last oil change so im going to stop adding it now.

Im a big fan of the VR1.. no issues at all.

Oil pressure is ~25 when HOT at idle Once im above 1200 RPM's oil pressure is 40+.

[Wagoneerxj]

I've been running Rotella 10W30 in the winter, and Rotella 15W40 in the summer in my XJ's. Stock 4.0's for now

[cruiser54]

I use 15/40 Rotella year round. I see temps as low as 0*F in the winter and as high as 100*F in summer.
Here is a quote from the factory owner's manual in 1989:

Jeep Engine Oil Viscosity

This was taken from pages 82 and 83 of the 1989 Chrysler/Jeep owners manual.

Selecting Engine Oil Viscosity

When changing or adding engine oil select the proper grade by using the chart on the following page. Select the grade that corresponds to the ambient temperature range you expect to encounter before your next oil change.

30*F to 100*F+ 20W-40 or 20W-50
0*F to 100*F+ 10W-30 or 10W-40
-20*F to 60*F 5W-30